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smsc75xx: Add workaround for gigabit link up hardware errata.

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In certain conditions, the device may not be able to link in gigabit mode. This software workaround ensures that the device will not enter the failure state.

Fixes: d0cad87170 ("SMSC75XX USB 2.0 Gigabit Ethernet Devices")
Signed-off-by: Yuiko Oshino <yuiko.oshino@microchip.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Yuiko Oshino 2018-07-03 11:21:46 -04:00 committed by David S. Miller
parent a659254755
commit d461e3da90
1 changed files with 62 additions and 0 deletions
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62
drivers/net/usb/smsc75xx.c
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@ -82,6 +82,9 @@ static bool turbo_mode = true;
module_param(turbo_mode, bool, 0644);
MODULE_PARM_DESC(turbo_mode, "Enable multiple frames per Rx transaction");
static int smsc75xx_link_ok_nopm(struct usbnet *dev);
static int smsc75xx_phy_gig_workaround(struct usbnet *dev);
static int __must_check __smsc75xx_read_reg(struct usbnet *dev, u32 index,
u32 *data, int in_pm)
{
@ -852,6 +855,9 @@ static int smsc75xx_phy_initialize(struct usbnet *dev)
return -EIO;
}
/* phy workaround for gig link */
smsc75xx_phy_gig_workaround(dev);
smsc75xx_mdio_write(dev->net, dev->mii.phy_id, MII_ADVERTISE,
ADVERTISE_ALL | ADVERTISE_CSMA | ADVERTISE_PAUSE_CAP |
ADVERTISE_PAUSE_ASYM);
@ -987,6 +993,62 @@ static int smsc75xx_wait_ready(struct usbnet *dev, int in_pm)
return -EIO;
}
static int smsc75xx_phy_gig_workaround(struct usbnet *dev)
{
struct mii_if_info *mii = &dev->mii;
int ret = 0, timeout = 0;
u32 buf, link_up = 0;
/* Set the phy in Gig loopback */
smsc75xx_mdio_write(dev->net, mii->phy_id, MII_BMCR, 0x4040);
/* Wait for the link up */
do {
link_up = smsc75xx_link_ok_nopm(dev);
usleep_range(10000, 20000);
timeout++;
} while ((!link_up) && (timeout < 1000));
if (timeout >= 1000) {
netdev_warn(dev->net, "Timeout waiting for PHY link up\n");
return -EIO;
}
/* phy reset */
ret = smsc75xx_read_reg(dev, PMT_CTL, &buf);
if (ret < 0) {
netdev_warn(dev->net, "Failed to read PMT_CTL: %d\n", ret);
return ret;
}
buf |= PMT_CTL_PHY_RST;
ret = smsc75xx_write_reg(dev, PMT_CTL, buf);
if (ret < 0) {
netdev_warn(dev->net, "Failed to write PMT_CTL: %d\n", ret);
return ret;
}
timeout = 0;
do {
usleep_range(10000, 20000);
ret = smsc75xx_read_reg(dev, PMT_CTL, &buf);
if (ret < 0) {
netdev_warn(dev->net, "Failed to read PMT_CTL: %d\n",
ret);
return ret;
}
timeout++;
} while ((buf & PMT_CTL_PHY_RST) && (timeout < 100));
if (timeout >= 100) {
netdev_warn(dev->net, "timeout waiting for PHY Reset\n");
return -EIO;
}
return 0;
}
static int smsc75xx_reset(struct usbnet *dev)
{
struct smsc75xx_priv *pdata = (struct smsc75xx_priv *)(dev->data[0]);